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J. FRANCO.

TRACTOR TREAD.

APPLICATION FILED FEB. 21, 1918.

1,305,593 a Patented J 11116 3, 1919.

1 m A TTORNE 1 3 JDHN FRANCO, OE SAN FRANCISCO, GALXFQRNIA.

TRACTOR-THEM Application filed February 21, 1918. Serial No. 23.8;13".

fl) a]! w/min it may concern:

lie it known that I, Join: FRANCO, a citizen oi tiwitzerland, and a resident of the city' and county of San l rai'icisco and State ol' t alit'ornia, have invented a certain new and useful T"actor-Trudi, of which the following is a specification.

The invention relates to endless treads or tracks for tractors of the caterpillar or track laying type.

in object of the ivention is to provide a tractor tread composed of a plurality of hinged links or plates having overlapping edgns which ii above the ground engaging surfaces at the plates.

Another oliject ot the invention is to provide a tread lorined of hinged plates in which dirt or earth cannot lhdge and pack in the joints between the successive plates. fr lurther ohiect ot' the invention is to .provide means for PIOVtllhlIiQ the hingepin lroni rotating in its hearings.

The invention possesses other advantageous features, some of which, with the foregoing. will be set forth at length in the 'l'ollowing description where I shall outline in tail that tern: of the invention which I have selected for illustration in the drawlli flfi :n'coinpanying and forming part oi the present. specific: i'lOlL in the drawings I have shown one specific i'orin oi tread plate but it is to he understood that l do not limit lli vfili 'l to such "form, since the invention, as

flat low projections 10 which serve as seats through whichholes may he formed for l'JOlli ing grousers or other extension plates to the plates. On its upper side the late is provided at one end with a central disposed cylindrical eye or hinge knuckle and at its other end is provided with spaced complementary eyes 5, adapted to lie adjacent ie ends of the. eye 4: on the adjacent plate 2 and form therewith a hinge lvinnclqle. The holes through the eyes 4- and are of the same diameter and the hin 'e completed by the belt or hinge pin e. ending through the eyes. The outer sin-laces or the eyes 5 are spaced inwardly from the side edges of the plates and a boss 7 is formed on the under side of the plate between each eye 5 and the side edge of the plate. The bolt (3 provided on its end with a srpiare head 8 which engages the, boss, thereby preventino the bolt from rotating in the eyes. .lfhe holt is preferably held against loin itndinal displacement by a cotterpin. t) passing through the end thereof.

The eye at has a cyrindr cal exterior surface and projects beyond tl ransverse ed ot' the plate and the eyes 5 have similar v lindrical exterior res and en. vond the other transverse edge and when the. plates are ass" oled the e vi and 5 overlap into axial alineinent transverse edges are brought into contac o approximate contact. i

exp! rd in the claims. may be embodied beyond the transverse of in a. plurality of "forms. are curved on their under snrjl' the cylindrical plane of the outer of the eyes surfaces of the bosses are 001 ntric with the bolt 6. These bosses and eg s overlie the transverse edge of the adjacentv plate, forming overlapping joints at the oppi' ite sides of the plates which prevent the en trance of earth into the joint in such quark Referring to said drawingsl ignre l is a plan view ot the under or ground engaging side of .two connected tread. plates.

Fig. 2 is a plan view of the upper side of two connected tread plates.

Fi is a side elevation of two connected in other words. the undertill if 4- is a vertical section taken along tity as-to interfere wit its acti the we at the center line said plates. '7 center of the plate, or between the overlap The tread of my invention consists of a at the sides, the transverse edge of the other plurality of hinged tread plates 2, all of plate underlies the eye 4. on the li plate, the plates lieii'ig identical and being conforming an overlap in the opposite direestructed so that they tit together to form tion. Considering two hinged p ates, the lo 50 the tread. The plate is preferably rectangufirst plate overlaps the second at the si e lar in shape and is provided on its lower or edges and the second. overlaps the first at ground engaging surface with a. transverse the central part, which is that part which rib or projection3 arranged adjacent one end, lies between the edge overlapping portions. which forms a grouser or ground gripping The tread plates are arranged in alinei'nent lie 55 element. Adjacent the opposite end the and the overlapping portions are disposed plate is preferably provided with two spaced above the lower surfaces of the plates.

The eyes :1 and 5 are joined on the upper side of the plate by the ribs or tracks iii, the outer edges of which are preferably parallel to the side edges of the plate. lit the end Where it meets the eye i: the outer edges of the tracks are turned in to meet the ends of the eye a to provide spaces for the eyes on the next plate, and at the other end of the plate the tracks merge into the eyes in In fact, the eyes 5 form parts of the tracks, The tracks are oi the same height as the eyes, so that a fiat-surfaced track is formed longitudinally of each plate. At their ends adjacent the eye the tracks are undorcitit to lighten the plate.

I claim:

1. An endless tractor tread composed of a. plurality of tread plates arranged in alinement, hinge joints eoi'inecting said plates together, extensions on one plate overlapping the hinge joint With the contiguous platii adjacent the side edges thereof, and an eXtension on the contiguous plate overlapping the hinge joint with the first platehetween the said side extensions.

2. An endless tractor tread composed of a plurality oi. hinge tread plates arranged in alinement, each plate having an eye on, one enzh and a plurality of eyes on the other enih the eye on one end lining alined axially With the eyes on the other and ol the next contiguous plate an extension on one plate between the eyes on one end overlapping the eye on the next contigiuius plate, and in contact with the surface tl'iereo't and extensions on the other end of the plate. at. the sides of the eye and overlapping the eyes on the nextcontiguons plate.

3. An endless tractor tread composed of a plurality oli ground engaging tread plates arranged in alinenient, an eye on one end oi each plate, a plurality of eyes on the other end of each plate, the eye on one plate being alined axially with the plurality of eyes on and a plurality of spaced projecting: eyes on a the other end overlying; the next contiguous plate at that end, and disposed on opposite sides of the central eye on said next eontiguous plate and projections extending transversely outward from said second mentioned eyes and owrlying; the next contiguous plate on the sides of said centrally disposed projecting eye. v

a. fin endless tractor tread composed of a plurality of hinged tread plates each having a rentrally disposed cylindrical eye on one end overlying the next contiguous plate. and a plurality of i-ipaecd cylindrical ey ,H on the other and overlying the next contiguoui plate at tile! end and arranged in alinement with the central eye on the next continuous plilllh a hinge pin extending through said allucd eyes and. projections having curred under surfaces concentric with said hinge pin extending from one plate adjacent said second mentioned eyes and overlying the next contiguous plate at the sides of its surface and a central projection on the said next contignious plate between said eyes overlying the said first plate at the center of its surface.

In testimony Whcreofi have hereunto set my hand at San l ranoiseo, California, this 9th day of February, 1918.

JGHN FRANCO. in presence ot- H. (it Pacer, 

